JSTests/test262/test/language/expressions/arrow-function/dstr/dflt-ary-ptrn-elem-id-iter-val-array-prototype.js

// This file was procedurally generated from the following sources:
// - src/dstr-binding/ary-ptrn-elem-id-iter-val-array-prototype.case
// - src/dstr-binding/default/arrow-function-dflt.template
/*---
description: Array destructuring uses overriden Array.prototype[Symbol.iterator] (arrow function expression (default parameter))
esid: sec-arrow-function-definitions-runtime-semantics-evaluation
features: [Symbol.iterator, generators, destructuring-binding, default-parameters]
flags: [generated]
info: |
    ArrowFunction : ArrowParameters => ConciseBody

    [...]
    4. Let closure be FunctionCreate(Arrow, parameters, ConciseBody, scope, strict).
    [...]

    9.2.1 [[Call]] ( thisArgument, argumentsList)

    [...]
    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
    [...]

    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )

    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
    [...]

    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)

    [...]
    23. Let iteratorRecord be Record {[[iterator]]:
        CreateListIterator(argumentsList), [[done]]: false}.
    24. If hasDuplicates is true, then
        [...]
    25. Else,
        b. Let formalStatus be IteratorBindingInitialization for formals with
           iteratorRecord and env as arguments.
    [...]

    Runtime Semantics: IteratorBindingInitialization

    SingleNameBinding : BindingIdentifier Initializer_opt

    1. Let bindingId be StringValue of BindingIdentifier.
    2. Let lhs be ? ResolveBinding(bindingId, environment).
    3. If iteratorRecord.[[Done]] is false, then
        a. Let next be IteratorStep(iteratorRecord).
        b. If next is an abrupt completion, set iteratorRecord.[[Done]] to true.
        c. ReturnIfAbrupt(next).
        d. If next is false, set iteratorRecord.[[Done]] to true.
        e. Else,
            i. Let v be IteratorValue(next).
            ii. If v is an abrupt completion, set iteratorRecord.[[Done]] to true.
            iii. ReturnIfAbrupt(v).
    [...]
    7. Return InitializeReferencedBinding(lhs, v).

---*/
Array.prototype[Symbol.iterator] = function* () {
    if (this.length > 0) {
        yield this[0];
    }
    if (this.length > 1) {
        yield this[1];
    }
    if (this.length > 2) {
        yield 42;
    }
};

var callCount = 0;
var f;
f = ([x, y, z] = [1, 2, 3]) => {
  assert.sameValue(x, 1);
  assert.sameValue(y, 2);
  assert.sameValue(z, 42);
  callCount = callCount + 1;
};

f();
assert.sameValue(callCount, 1, 'arrow function invoked exactly once');